// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_RENDERER_PEPPER_PEPPER_GRAPHICS_2D_HOST_H_
#define CONTENT_RENDERER_PEPPER_PEPPER_GRAPHICS_2D_HOST_H_

#include <stdint.h>

#include <vector>

#include "base/compiler_specific.h"
#include "base/macros.h"
#include "base/memory/weak_ptr.h"
#include "content/common/content_export.h"
#include "ppapi/c/ppb_graphics_2d.h"
#include "ppapi/host/host_message_context.h"
#include "ppapi/host/resource_host.h"
#include "third_party/WebKit/public/platform/WebCanvas.h"
#include "ui/gfx/geometry/point.h"
#include "ui/gfx/geometry/point_f.h"
#include "ui/gfx/geometry/size.h"

namespace cc {
class SharedBitmap;
class SingleReleaseCallback;
class TextureMailbox;
}

namespace gfx {
class Rect;
}

namespace gpu {
struct SyncToken;
}

namespace content {

class PepperPluginInstanceImpl;
class PPB_ImageData_Impl;
class RendererPpapiHost;

class CONTENT_EXPORT PepperGraphics2DHost
    : public ppapi::host::ResourceHost,
      public base::SupportsWeakPtr<PepperGraphics2DHost> {
public:
    static PepperGraphics2DHost* Create(
        RendererPpapiHost* host,
        PP_Instance instance,
        PP_Resource resource,
        const PP_Size& size,
        PP_Bool is_always_opaque,
        scoped_refptr<PPB_ImageData_Impl> backing_store);

    ~PepperGraphics2DHost() override;

    // ppapi::host::ResourceHost override.
    int32_t OnResourceMessageReceived(
        const IPC::Message& msg,
        ppapi::host::HostMessageContext* context) override;
    bool IsGraphics2DHost() override;

    bool ReadImageData(PP_Resource image, const PP_Point* top_left);
    // Assciates this device with the given plugin instance. You can pass NULL
    // to clear the existing device. Returns true on success. In this case, a
    // repaint of the page will also be scheduled. Failure means that the device
    // is already bound to a different instance, and nothing will happen.
    bool BindToInstance(PepperPluginInstanceImpl* new_instance);
    // Paints the current backing store to the web page.
    void Paint(blink::WebCanvas* canvas,
        const gfx::Rect& plugin_rect,
        const gfx::Rect& paint_rect);

    bool PrepareTextureMailbox(
        cc::TextureMailbox* mailbox,
        std::unique_ptr<cc::SingleReleaseCallback>* release_callback);
    void AttachedToNewLayer();

    // Notifications about the view's progress painting.  See PluginInstance.
    // These messages are used to send Flush callbacks to the plugin.
    void ViewInitiatedPaint();

    float GetScale() const;
    void SetLayerTransform(float scale, const PP_Point& transform);
    bool IsAlwaysOpaque() const;
    PPB_ImageData_Impl* ImageData();
    gfx::Size Size() const;

    void ClearCache();

    void set_viewport_to_dip_scale(float viewport_to_dip_scale)
    {
        DCHECK_LT(0, viewport_to_dip_scale_);
        viewport_to_dip_scale_ = viewport_to_dip_scale;
    }

private:
    PepperGraphics2DHost(RendererPpapiHost* host,
        PP_Instance instance,
        PP_Resource resource);

    bool Init(int width,
        int height,
        bool is_always_opaque,
        scoped_refptr<PPB_ImageData_Impl> backing_store);

    int32_t OnHostMsgPaintImageData(ppapi::host::HostMessageContext* context,
        const ppapi::HostResource& image_data,
        const PP_Point& top_left,
        bool src_rect_specified,
        const PP_Rect& src_rect);
    int32_t OnHostMsgScroll(ppapi::host::HostMessageContext* context,
        bool clip_specified,
        const PP_Rect& clip,
        const PP_Point& amount);
    int32_t OnHostMsgReplaceContents(ppapi::host::HostMessageContext* context,
        const ppapi::HostResource& image_data);
    int32_t OnHostMsgFlush(ppapi::host::HostMessageContext* context);
    int32_t OnHostMsgSetScale(ppapi::host::HostMessageContext* context,
        float scale);
    int32_t OnHostMsgSetLayerTransform(ppapi::host::HostMessageContext* context,
        float Scale,
        const PP_FloatPoint& Transform);
    int32_t OnHostMsgReadImageData(ppapi::host::HostMessageContext* context,
        PP_Resource image,
        const PP_Point& top_left);

    // If |old_image_data| is not NULL, a previous used ImageData object will be
    // reused.  This is used by ReplaceContents.
    int32_t Flush(PP_Resource* old_image_data);

    // Called internally to execute the different queued commands. The
    // parameters to these functions will have already been validated. The last
    // rect argument will be filled by each function with the area affected by
    // the update that requires invalidation. If there were no pixels changed,
    // this rect can be untouched.
    void ExecuteTransform(const float& scale,
        const gfx::PointF& translate,
        gfx::Rect* invalidated_rect);
    void ExecutePaintImageData(PPB_ImageData_Impl* image,
        int x,
        int y,
        const gfx::Rect& src_rect,
        gfx::Rect* invalidated_rect);
    void ExecuteScroll(const gfx::Rect& clip,
        int dx,
        int dy,
        gfx::Rect* invalidated_rect);
    void ExecuteReplaceContents(PPB_ImageData_Impl* image,
        gfx::Rect* invalidated_rect,
        PP_Resource* old_image_data);

    void SendFlushAck();

    // Function scheduled to execute by ScheduleOffscreenFlushAck that actually
    // issues the offscreen callbacks.
    void SendOffscreenFlushAck();

    // Schedules the offscreen flush ACK at a future time.
    void ScheduleOffscreenFlushAck();

    // Returns true if there is any type of flush callback pending.
    bool HasPendingFlush() const;

    // Scale |op_rect| to logical pixels, taking care to include partially-
    // covered logical pixels (aka DIPs). Also scale optional |delta| to logical
    // pixels as well for scrolling cases. Returns false for scrolling cases where
    // scaling either |op_rect| or |delta| would require scrolling to fall back to
    // invalidation due to rounding errors, true otherwise.
    static bool ConvertToLogicalPixels(float scale,
        gfx::Rect* op_rect,
        gfx::Point* delta);

    void ReleaseCallback(std::unique_ptr<cc::SharedBitmap> bitmap,
        const gfx::Size& bitmap_size,
        const gpu::SyncToken& sync_token,
        bool lost_resource);

    RendererPpapiHost* renderer_ppapi_host_;

    scoped_refptr<PPB_ImageData_Impl> image_data_;

    // Non-owning pointer to the plugin instance this context is currently bound
    // to, if any. If the context is currently unbound, this will be NULL.
    PepperPluginInstanceImpl* bound_instance_;

    // Keeps track of all drawing commands queued before a Flush call.
    struct QueuedOperation;
    typedef std::vector<QueuedOperation> OperationQueue;
    OperationQueue queued_operations_;

    // True if we need to send an ACK to plugin.
    bool need_flush_ack_;

    // When doing offscreen flushes, we issue a task that issues the callback
    // later. This is set when one of those tasks is pending so that we can
    // enforce the "only one pending flush at a time" constraint in the API.
    bool offscreen_flush_pending_;

    // Set to true if the plugin declares that this device will always be opaque.
    // This allows us to do more optimized painting in some cases.
    bool is_always_opaque_;

    // Set to the scale between what the plugin considers to be one pixel and one
    // DIP
    float scale_;

    // The scale between the viewport and dip.
    float viewport_to_dip_scale_ = 1.0f;

    ppapi::host::ReplyMessageContext flush_reply_context_;

    bool is_running_in_process_;

    bool texture_mailbox_modified_;

    // This is a bitmap that was recently released by the compositor and may be
    // used to transfer bytes to the compositor again.
    std::unique_ptr<cc::SharedBitmap> cached_bitmap_;
    gfx::Size cached_bitmap_size_;

    friend class PepperGraphics2DHostTest;
    DISALLOW_COPY_AND_ASSIGN(PepperGraphics2DHost);
};

} // namespace content

#endif // CONTENT_RENDERER_PEPPER_PEPPER_GRAPHICS_2D_HOST_H_
